package org.apache.solr.analysis;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.payloads.DelimitedPayloadTokenFilter;
import org.apache.lucene.analysis.payloads.PayloadEncoder;
import org.apache.lucene.analysis.payloads.FloatEncoder;
import org.apache.lucene.analysis.payloads.IntegerEncoder;
import org.apache.lucene.analysis.payloads.IdentityEncoder;
import org.apache.solr.common.ResourceLoader;
import org.apache.solr.common.SolrException;
import org.apache.solr.util.plugin.ResourceLoaderAware;

import java.util.Map;

/**
 * 
 * Factory for {@link DelimitedPayloadTokenFilter}.
 * 
 * <pre class="prettyprint" >
 * &lt;fieldType name="text_dlmtd" class="solr.TextField" positionIncrementGap="100"&gt;
 *   &lt;analyzer&gt;
 *     &lt;tokenizer class="solr.WhitespaceTokenizerFactory"/&gt;
 *     &lt;filter class="solr.DelimitedPayloadTokenFilterFactory" encoder="float" delimiter="|"/&gt;
 *   &lt;/analyzer&gt;
 * &lt;/fieldType&gt;
 * </pre>
 * 
 * @version $Id$
 * 
 */
public class DelimitedPayloadTokenFilterFactory extends BaseTokenFilterFactory
		implements ResourceLoaderAware {
	public static final String ENCODER_ATTR = "encoder";
	public static final String DELIMITER_ATTR = "delimiter";

	private PayloadEncoder encoder;
	private char delimiter = '|';

	public DelimitedPayloadTokenFilter create(TokenStream input) {
		return new DelimitedPayloadTokenFilter(input, delimiter, encoder);
	}

	@Override
	public void init(Map<String, String> args) {
		super.init(args);
	}

	public void inform(ResourceLoader loader) {
		String encoderClass = args.get(ENCODER_ATTR);
		if (encoderClass.equals("float")) {
			encoder = new FloatEncoder();
		} else if (encoderClass.equals("integer")) {
			encoder = new IntegerEncoder();
		} else if (encoderClass.equals("identity")) {
			encoder = new IdentityEncoder();
		} else {
			encoder = (PayloadEncoder) loader.newInstance(encoderClass);
		}

		String delim = args.get(DELIMITER_ATTR);
		if (delim != null) {
			if (delim.length() == 1) {
				delimiter = delim.charAt(0);
			} else {
				throw new SolrException(SolrException.ErrorCode.SERVER_ERROR,
						"Delimiter must be one character only");
			}
		}
	}
}